1. Field of the Invention
The present invention relates to current measurements associated with an electronic control module (ECU), such as but not limited to current measurements occur during sleep mode operation of the ECU.
2. Background Art
The functionality and the complexity of a vehicle or other device requiring an electronic control module (ECU) are continuously increasing. With additional devices needing electronic control and related operations, the number of ECUs on the vehicles, as well as the necessary wiring and costs to support the corresponding operations, are rising.
Examples to manage the costs as well the system complexity may include ECU networking via bus systems (virtual sensory, distributed intelligence and functions), increasing integration of the ECUs (more functions per ECU), and/or replacing relays with power semiconductors. This cost management, however, generally results in the need for a bus to facilitate controlling ECUs, which requires the ECUs and the modules that they control to be constantly powered in order to receive bus signals.
The ECUs may operate in active and inactive state. The active state corresponds with the ECU being normally powered and fully operation of the modules. The inactive state, commonly referred to as sleep mode, corresponds with the ECU be minimally powered such that the modules are inactive but provided with a minimal current so as to facilitate receipt and operation in response to the bus signals.
As one skilled in the art will appreciate, the modules and other features of the ECU may defective, either at the time of installation or thereafter, for any number of reasons, such as but not limited to ESD, mechanical stress, internal/external corrosion and/or any number of other influences. The defects when the ECU are active are easily detectable by the loss or inoperability of the function associated with the defective module. Defects not associated with loss of the modules or during sleep mode when the modules are inactive are not detected, typically at least until the module fails or the ECU is activated.